It is often necessary to move bulk materials such as sand, gravel, mineral ore, grain, flour, sawdust, dry chemicals and other granular or pelletized material from one place to another along a horizontal, an inclined or a generally vertical path. One way to move such bulk materials is with what are now commonly called "en masse" conveyors. Such conveyors typically have an elongated housing, essentially square or rectangular in cross-section, through which an endless conveyor chain is pulled by a suitable power driven sprocket wheel, usually located adjacent the discharge end of the conveyor.
Located below a loose pile, a storage bin or some other supply device of the bulk material, the conveyor housing includes a supply or inlet opening through which the bulk material flows so as to completely fill the interior, material-conveying, cross-section of the housing. At a point where the bulk material is to be delivered, the conveyor housing is provided with an outlet opening through which the bulk material exits into a discharge pile, another storage bin, or into the hopper or tank of a transportation vehicle such as a truck trailer, rail car or ship's hold.
The conveyor chain is typically made up of a plurality of longitudinally extending links connected to one another by articulated joints and a plurality of generally transversely extending paddles or flights which engage and convey the bulk material along inside the conveyor housing. Because the bulk material fills substantially the entire internal, material-conveying, cross-section of the conveyor housing from the inlet opening to the outlet opening, the material is moved by and with the conveyor chain essentially as a moving column of material with very little shear or slippage between the conveyor chain and the bulk material. This form of movement, of course, is what gives rise to the name "en masse" conveyor or elevator.
Conveyors of the foregoing type are also sometimes referred to as "Redler Conveyors" after the name of the original inventor. U.S. Pat. Nos. 1,999,484 and 2,290,077 issued to Alfred De Los Sinden and assigned to the Redler Conveyor Company are illustrative of the general configuration of such conveyors. The earlier one of these patents shows the conveyor flights formed integrally with the tension or drawbar elements of the conveyor chain. Conveyors of this type are still being sold commercially, but they require complete replacement of the integral chain link and flight if the original flight is damaged or if a different flight configuration is desired. This requires disassembly of the conveyor chain and is both time consuming and expensive. The latter Sinden patent discloses bolt on conveyor flights but these have met with only limited success due to the difficulty often encountered in gaining access to the connecting bolts and removing them, particularly after the bolt threads become frozen in their sockets due to rust, corrosion or other foreign material.